This invention relates to ventilators for installation on outside walls of cargo containers and, more particularly, to ventilators of unitary construction which are readily installable on marine cargo containers and are highly serviceable thereon.
Cargo containers are constructed of rigid walls and may include additional struts for buttressing the strength of the container for holding securely a variety of items of differing sizes and weights during transportation in or on a vehicle such as a ship, train, or airplane. Of particular interest are marine cargo containers which may be transported on open decks of ships and, hence, are subjected to extremes in weather conditions including large changes in temperature and humidity as well as wind and rain.
It is common practice to provide such containers with ventilation which permits flow of air from outside into the container and visa versa. Such ventilation protects contents of the containers from condensation of water vapor in the air, and also protects the contents from excessively high solar heating by offering a measure of cooling.
Typically, such a ventilator comprises an opening in an outer wall of the container and some form of outer housing with apertures therein for admission of air, the housing being configured with baffles to deflect wind forces in a rainstorm to prevent wetting of the contents of the container.
A problem arises in construction of these ventilators in that the sidewall of the container is constructed with various ribs and baffles protruding therefrom to become part of the ventilator. The housing, which may also include a baffle, is then secured to the container wall such that the two baffles are positioned relative to each other to provide a sinuous path for air flow from apertures in the housing to the opening in the container wall.
The sinuous path aids in deflecting the rain and wind from the interior of the container. Typically the apertures are disposed on a lower wall of the housing with the sinuous path extending in a generally upward direction.
This form of construction is disadvantageous in that the construction of the ventilator is unduly complicated. The aforementioned adaptation of the container wall to include specific components of the ventilator complicates both the fabrication of the ventilator and that of the container. Since containers generally are formed of steel plates, the foregoing construction requires formation of the ventilator elements by steel forming techniques which may include pressing, riveting, and welding. In addition, the ventilator may have to be disassembled periodically to inspect for frost and corrosion, which corrosion would necessitate replacement of the entire ventilator. And, as a further disadvantage, co-ordination is required by the manufacturer of the container and the manufacturer of the remaining portions of the ventilator, to provide precise mating of the various components thereof. Also the construction of the housing and any baffles and supporting structures therein can introduce complex assembly procedures when such components are to be secured in position by welding or riveting.